In-band pumping of Nd-vanadate thin-disk lasers

We investigate the output performance of the 1.06 mu m(4)F(3/2)-->I-4(11/2) transition in Nd:GdVO4 and Nd:YVO4 thin-disk lasers under multi-pass pumping with diode lasers at 0.81 mu m and at 0.88 mu m, which corresponds to direct in-band pumping of the F-4(3/2) emitting level. The use of a pump module with 24 passes through the crystal allowed the realization of an in-band pumped Nd:GdVO4 thin-disk laser with 14.9 W of continuous wave (cw) output power at 1.06 mu m; the overall optical-to-optical efficiency was 0.50 and the slope efficiency with respect to the incident pump power was 0.52. Intracavity frequency-doubling of the Nd:GdVO4 thin-disk laser with a LiB3O5 (LBO) nonlinear crystal yielded 9.1 W of cw output power in the green at 0.53 mu m with an overall optical-to-optical efficiency of 0.31.